Which of the following is (are) V-shaped?

Options

A. `S_(3)^(2-)`
B. `I_(3)^(-)`
C. `N_(3)^(-)`
D. `I_(3)^(+)`

Answer

To determine which of the given species are V-shaped, we need to analyze the molecular geometry of each species based on the number of bonding pairs and lone pairs of electrons around the central atom. The V-shaped (or bent) geometry typically occurs when there are two bonding pairs and one or more lone pairs of electrons.

### Step-by-Step Solution:

1. **Identify the Species**: The species we need to analyze are \( S_3^{2-} \), \( I_3^{-} \), \( N_3^{-} \), and \( I_3^{+} \).

2. **Analyze \( S_3^{2-} \)**:
- Sulfur (S) has 6 valence electrons. With a \( 2- \) charge, it gains 2 additional electrons, giving it a total of 8 valence electrons.
- In \( S_3^{2-} \), there are 2 sulfur atoms bonded to a central sulfur atom. The central sulfur atom has 2 lone pairs and forms 2 bonds.
- The presence of lone pairs and bond pairs results in a V-shaped structure.

3. **Analyze \( I_3^{-} \)**:
- Iodine (I) has 7 valence electrons. With a \( -1 \) charge, it gains 1 additional electron, giving it a total of 8 valence electrons.
- In \( I_3^{-} \), there are 3 iodine atoms. The central iodine atom has 2 bond pairs and 3 lone pairs.
- The geometry is linear due to the steric number of 5 (2 bond pairs + 3 lone pairs).

4. **Analyze \( N_3^{-} \)**:
- Nitrogen (N) has 5 valence electrons. With a \( -1 \) charge, it gains 1 additional electron, giving it a total of 6 valence electrons.
- In \( N_3^{-} \), there are 3 nitrogen atoms. The central nitrogen atom has 2 bond pairs and no lone pairs.
- The geometry is linear due to the steric number of 2 (2 bond pairs + 0 lone pairs).

5. **Analyze \( I_3^{+} \)**:
- Iodine (I) has 7 valence electrons. With a \( +1 \) charge, it loses 1 electron, giving it a total of 6 valence electrons.
- In \( I_3^{+} \), there are 3 iodine atoms. The central iodine atom has 2 bond pairs and 2 lone pairs.
- This results in a V-shaped structure due to the presence of lone pairs.

### Conclusion:
The species that are V-shaped are:
- \( S_3^{2-} \)
- \( I_3^{+} \)

### Summary:
- **V-shaped species**: \( S_3^{2-} \) and \( I_3^{+} \)
- **Not V-shaped**: \( I_3^{-} \) and \( N_3^{-} \)